Detectives investigating the firebomb attacks along the Boucher Road in south Belfast last Wednesday want to speak to a motorist seen in the area.
The police have appealed for information about this car
The driver of a blue Toyota with a taxi sign dropped off a passenger at the Shane Retail Park on Halloween at about 1930 GMT on the eve of the fires.
Dissident republicans were blamed for the attacks.
Senior investigating officer, Detective Chief Inspector Raymond Ramsey, said the taxi driver may be able to help.
"You may have dropped a passenger off at the retail park, and may have information that could be of assistance to this investigation," he said.
The attacks saw a Homebase store destroyed and other properties damaged. There was also an attack on a sports shop in Anne Street in the city centre.
At its height, more than 70 firefighters attended the blaze at the Homebase store, which also spread to Reid's furniture store next door.